Tomorrow Julian Arnold will tell us about his master's thesis project, on "Entropy production in ticking clocks". See below for the abstract. We start at 2pm in zoom: https://ethz.zoom.us/j/362994444

Best,
Joe


Abstract:
The concept of time and its role in physics, in particular quantum theory, remains an active field of research. The act of timekeeping is linked to the usage of clocks as reference systems. Thus, many open questions about time can be addressed through the study of these devices. Ticking clocks provide information about the flow of time in terms of discrete ``ticking'' events. In this thesis, we studied autonomous ticking clocks based on a model derived from axiomatic principles [M. P. Woods, Quantum 5, 381 (2021)]. We tried to answer the question whether the theory of quantum information imposes any constraints on the relation between the entropy production per tick of a ticking clock and its accuracy. Here, the entropy production serves as a measure for the exchanged information between a ticking clock and its outside. We find that there exist quantum ticking clocks with coherent internal dynamics that approach infinite accuracy at zero entropy production per tick. In contrast, ticking clocks whose state remains incoherent at all times must produce a minimal amount of entropy in each tick that increases with increasing accuracy. For such clocks the entropy production per tick acts as a fundamental resource for measuring time.